Proposal of a Parameterized Methodology for the Hydrodynamic Design of High-Efficiency Pelton Rotors Validated by Multiphase CFD Simulations

This work presents and validates a direct analytical methodology for the parametric hydrodynamic design of Pelton rotors. The proposed approach combines a one-dimensional theoretical framework for defining global geometric rotor parameters with an inductive method for generating bucket geometry, formalized from a comprehensive mapping of a high-efficiency commercial reference bucket. The reliability of this integrated design methodology is assessed via high-fidelity unsteady Reynolds-averaged Navier–Stokes (URANS) computational fluid dynamics (CFD) simulations, coupled with the volume of fluid (VOF) multiphase model and the k−ω SST turbulence model on a rotating five-bucket domain. A theoretical efficiency of 93.4% was estimated, closely aligning with the 91.4% total efficiency obtained from the CFD model. Furthermore, simulations under part-load conditions demonstrated the designed rotor's high performance, with efficiency remaining above 85% in all off-design scenarios. Finally, the proposed methodology provides a practical, reproducible, and computationally efficient tool for generating high-performance geometries, serving as a robust foundation for integrating into future optimization workflows, fluid-structure interaction analyses, and advanced research in Pelton turbine design.